What environment is necessary for pyrolysis to occur?

For pyrolysis to occur, it is essential to have an oxygen-free environment. This process involves the thermal decomposition of organic material at elevated temperatures in the absence of oxygen. When oxygen is present, combustion occurs instead, leading to the complete oxidation of the material rather than its breakdown into smaller molecules. In an oxygen-free environment, the organic material can break down into various products, including gases, oils, and char, without being burnt away.

Other environments mentioned, like an oxidizing or aerobic environment, would lead to oxidation rather than pyrolysis, which is why they would be unsuitable for this process. A high humidity environment is not a necessary condition for pyrolysis either, as it focuses primarily on the absence of oxygen rather than the presence of moisture.